The number of tigers in the wild have increased for the first time after decades of decline, conservationists have said.
A new global estimate based on the best available data suggests there are at least 3,890 wild tigers in the world, an increase on the previous figure of "as few as 3,200" in 2010.
Wildlife charity WWF said the figures, compiled from International Union for Conservation of Nature (IUCN) data and the latest national tiger surveys by some countries, were the first time in tiger conservation history that global numbers have increased.
The boost is down to increases in tiger populations in India, Russia, Nepal and Bhutan, better surveys and enhanced protection of the species, WWF said.
The rise has been announced ahead of a key meeting in India on tiger conservation at the half way point in a 12-year "Tx2" plan, by countries where tigers are or have been found, to double numbers of the species by 2022.
But WWF said more needed to be done to protect the endangered species.
Marco Lambertini, director general of WWF International, said: "For the first time after decades of constant decline, tiger numbers are on the rise.
"This offers us great hope and shows that we can save species and their habitats when governments, local communities and conservationists work together."
Michael Baltzer, leader of WWF's Tx2 tiger initiative, called for a strong action plan for the next six years by countries with tigers.
"The global decline has been halted but there is still no safe place for tigers.
"South East Asia, in particular, is at imminent risk of losing its tigers if these governments do not take action immediately."
WWF wants to see those countries which have not met their commitment to update their population figures by 2016 based on national surveys to do so.
Countries need to know their tiger populations and the threats they face, such as poaching for skins and body parts and loss of their habitat, in order to protect them, the charity argues.
Ahead of the summit, other environmental groups have called on countries to commit to ending "tiger farming" for their skins and parts for medicine, which they say stimulates demand for such products and puts more poaching pressure on wild tigers.
Meanwhile, tribal people's rights organisation Survival International has accused authorities in India of forcibly moving indigenous people from their homes in areas designated as tiger reserves.
Hollywood star and environmental campaigner Leonardo DiCaprio, who created the Leonardo DiCaprio Foundation and is a member of the WWF board, said: "Tigers are some of the most vital and beloved animals on Earth.
"With our partners at WWF, my foundation has supported major efforts to double the number of tigers in the wild.
"In Nepal, our efforts have produced one of the greatest areas of progress in tiger conservation, which is helping drive this global increase in population.
"I am so proud that our collective efforts have begun to make progress toward our goal, but there is still so much to be done.
"I am optimistic about what can be achieved when governments, communities, conservationists and private foundations like ours come together to tackle global challenges."